Although laser and IPL technology has not been known to cause skin cancer, this does not mean that laser and IPL therapies are without long-term risks.

If you look at the dot from a 10,000 mW (10 W) visible laser within 1.8 feet (60 cm) for more than 10 seconds, this could potentially cause a retinal burn. In summary, looking at a diffuse line of red light from a Class IIIa (3R) laser, even for a number of hours, will not cause any eye injury or damage.

Many laser pointers are in the range of 1 to 5 milliwatts (mW), a subclass of 3 called 3A. A close reading of exposure limits indicate that a 5 mW laser could cause eye damage.

Considering visible laser (e.g. red He-Ne laser), below about 50 mW you can close your eyes quickly enough that the energy absorbed is insufficient to cause permanent eye damage. If you intentionally stare into it, or the laser is invisible and does not trigger the eye reflex, a much weaker laser can blind you.

Under federal law, it is perfectly legal to sell any laser above 5 mW as long as the laser complies with FDA/CDRH laser product requirements for labels, safety features, quality control, etc. Of course, if a person uses a laser irresponsibly, then it may be confiscated.

Laser pointers can put out anywhere between 1 and 5 milliwatts of power, which is enough to damage the retina after 10 seconds of exposure. This can lead to permanent vision loss. That said, it can be very difficult to expose the retina to that much light for that long a time.

The limit for “safe” lasers is 5mW. They’re safe not because you can stare into them without danger, but because your blink reflex is quick enough (<0.25s) that you can shut your eyes (or turn your head) quickly enough before damage is done.